Microscopic organization of molecules in smectic A and chiral (racemic) smectic C phases: Dynamic molecular deformation effect on the SAto SC* (SC) transition
作者:
Atsushi Yoshizawa,
Hiroshi Kikuzaki,
Mitsuo Fukumasa,
期刊:
Liquid Crystals
(Taylor Available online 1995)
卷期:
Volume 18,
issue 3
页码: 351-366
ISSN:0267-8292
年代: 1995
DOI:10.1080/02678299508036633
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
We investigated the correlation between orientational order and microscopic organization of the molecules in smectic A and chiral (racemic) smectic C phases by means of solid-state C-13 NMR, powder X-ray diffraction, and electrooptical measurements. The compounds under investigation are 4-((S)-2-methyloctanoyl)phenyl 4′-nonylbiphenyl-4-carboxylate ((S)-MONBIC) and its corresponding racemic compound ((S, R)-MONBIC). Static C-13 NMR indicates that: (1) the orientational angle of the tail with respect to the magnetic field decreases slightly both in the SAand S*Cphases as decreasing temperature, and (2) the angle of the core with respect to the field decreases in the SAphase but increases in the S*Cphase as decreasing temperature. Analysis of C-13T1reveals that the dynamic molecular deformation for the core part can occur near the transition. We discuss the dynamic molecular deformation in comparison with the reorientation of the director at the SAto S*Ctransition. Based on the experimental results, we propose the structural model in which describes the microscopic organization of the molecules in the mesophases.
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